Birds evolved from
a. insects.
b. a common ancestor with reptiles.
c. amphibians.
d. mammals.

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.

To store strawberries in sugar syrup, lucy placed them in a jar and covered them with sugar but did not add any water. do you think syrup will be formed? justify. a. no. since water is not added, there cannot be any syrup formation. b. no. the higher concentration of sugar on the outside will cause the water from the sugar to diffuse in the strawberry cells causing them to swell without formation of any syrup. c. yes. the higher concentration of sugar on the outside will cause the water from the strawberry to diffuse out resulting in syrup formation. d. yes. the sugar will melt over time and form the syrup.